Display posts grouped by category and author

CMS & WordPress
1

I am trying to do Group by Category and Author and display posts in Wordpress but have been unsuccessful. Single grouping works.
Like I can either group by Author or Category but not both

Here is what I am able to achieve

Category Name 1

[INDENT]+ Post 1

  • Post 2
  • Post 3[/INDENT]

Category Name 2

[INDENT]+ Post 4

  • Post 5
  • Post 6[/INDENT]

Similarly I am able to do this
Author Name 1

[INDENT]+ Post 1

  • Post 3
  • Post 5[/INDENT]

Author Name 2

[INDENT]+ Post 2

  • Post 4
  • Post 6
    [/INDENT]
    But I need to do this

Category Name 1

+ Author Name 1

[INDENT]+ Post 1

  • Post 3[/INDENT]

+ Author Name 2

+ Post 2

Category Name 2

+ Author Name 1

+ Post 5

+ Author Name 2

[INDENT]+ Post 4

  • Post 6[/INDENT]

Any help is highly appreciated.

2

Please post your working code and your attempt at the two tier.

3

nevermind figured out. I was not adding a group by author id to my query thats why it was not working.

we basically need to add a group by author to the query